Viscose complex



Patented Aug. 26, 1930 UNITED STATES PATENT OFFICE WILLIAM MENDEL, OFBEVERLY,-NEW JERSEY, ASSIGNOR TO SAMUEL EDGEWATER PARK, NEW JERSEYVISCOSE COMPLEX no Drawing. Application filed May as,

Conversion of liquid viscose (cellulose sulcellulose hydrate for theproduction of fila ments and films, by various methods and means, isWell known. For instance, such conversionmay be, effected byprogressively projecting a stream of viscose into anaqueous solutioncontaining a suitable acid, or acid salt, either With or Withoutn'eutralsalts or dehydrators, or both, or by the mere action of heat,Without the employment of such chemicals. 'However, an essential step inall such processes is What is termed the aging of the viscose to thedesired degree of maturity, manifestedby such polymerization ofthemolecule as to permit it to be more easily disorganized in thecoagulating medium,'and with the so-called normal viscose containing 110 to the amount of seven per cent, the time Which is required for theviscose to attain the desired degree of maturity aforesaid is not onlyan important factor in the cost of production of the ultimate filamentor film product, but also in the capacity for production thereof by anyapparatus.

Therefore, the principal purpose and effect of my invention hereincontemplated is to so initially modify the viscose complex thatformation of insoluble sulphur complexes is prevented although thedesired aging may be accelerated to any desired degree, to thus increasethe capacity for production of any suitable apparatus and lessen thecost of the product aforesaid.

The aforesaid conversion of viscose by coagulation and ultimatesolidification by the usual means above indicated, is attended byliberation of sulphur and its derivatives, some of which are insolubleand adherent to the product to the detriment of the latter, as theydetract from all of the qualities which make such filaments and filmscommercially valuable, especially their luster, strength and elasticity.

During an extended research for means to 1925. Serial No. 32,452.

effectively remove sulphur and its derivatives from the precipitatedcellulose hydrate, I dis covered that the action of tri-sodium phosphate (Na PO upon the cellulose hydrate removes all of such deleteriousmatter and the use of that chemical for that purpose at different stagesin the conversion of viscose to solid form is the subject matter ofseveral of my applications for Letters Patent of the United Statescopending herewith, for in stance, Serial No. 26,825 pursuant to WhichLetters Patent No. 1,57 6,529 Were granted March 16, 1926. However,during that research, I also discovered that if the PO ion be added to,or formed in the viscose, preliminary to or during the aforesaid agingstage thereof, the latter is facilitated-in accordance with the amountof said PO ion present in the viscose complex, and the matured viscoseis much more stable. For instance, although norma]. viscose ages slower,to the aforesaid mature state; it continues to change thereafter and,Within'a few hours, passes'toa state of over-matured Worthlessness;Whereas, although my improved viscose reaches such maturity quicker, itthereafter remains stable and Without apparent further change formonths; provided it is maintained at'a temperature of less than 18 C. Inother Words; by the addition of P0 ion to the normalviscose, the timeand consequent cost of product-ion of properly matured viscose, and ofthe ultimate products aforesaid may be very materially lessened and thecapacity of any given apparatus for such production cor respondinglyincreased, Without any alteration in such apparatus. Moreover, theaforesaid stability of my improved viscose avoids the difficultiesheretofore experienced in maintaining an adequate supply of spinnable"viscose from normal viscose.

For instance, viscose maybe prepared by first treating suitable Woodpulp or cotton having the typical formula C l-1 0 by steeping it in anaqueous solution of caustic soda of A. NEIDICH, OF

suitable strength; for instance, containing approximately twenty percent NaOH. Then pressing the mass to about three times the Weight of thedry cellulose; then grinding such ressed material, as fine as possible,and allowing it to stand for about 50 hours. The mass is then subjectedto the action of carbon bisulphide (CS conveniently during agitation ofthe mass, until the xanthate is formed, thus;

The xanthatc is then disselr'ed in aqueous solution, with or withoutcaustic soda, to which has been added the desired amount of PO. ion, inthe form of Na PO, or otherwise, in accordance with the cellulosecontent and alkalinity of the xanthate.

I find it convenient to add the desired proportion of tri-sodiumphosphate in aqueous solution to the viscose complex thus formed whenthe latter is in a substantially homogeneous liquid stage. llowever,said phosphate may be added to the viscose complex at an earlier orlater stage, with the eli'ect of more or less accelerating the :Wing ofthe viscose complex to the desired d g cc of maturity aforesaid inaccordance with the amount of PO. included in the viscose complex.However, I find that, in the a iiparatus with which I have experimented,for formation of thick wide films. the proportion of phosphate may befour and one-half per cent of the cellulose content of the viscose andyet allow time enough for said aging stage, to permit proper disposal ofthe viscose for subsequent treatment. That is to say, as a matter ofexpediency, the proportion of tri-sodium phosphate added to the viscosecomplex must be small enough. to permit the removal of the viscose forsubsequent use before it has so aged to pass the desired degree ofmaturity. For instance, if the viscose is desired for precipitation inthe form of thick filaments, upon plates or other carriers; it may beallowed to become more mature than if it is to be spun in minutefilaments. However, the precise [)lOPOItlOH of the phosphate for anydesired rate of aging of the viscose may be readily determined by actualtrial and should be limited as afore said by the facility with which theviscose may be handled; so as to maintain the maximum efficiency ofproduction of any given apparatus. However, the improvement in qualityof the products formed is apparently elfected regardless of the amountof P0 ion present, which may be a fraction of one per cent.

Of course, as above noted, the inclusion of P0 ion in the viscoseminimizes the production of deleterious sulphur compounds therein and,during the subsequent reversion of the viscose to solid form, the effectof such ions is to render the sulphur derivatives soluble so that theymay be readily rinsed from the coagulated cellulose hydrate.

Therefore, although I have described a typicalembodiment of my inventionI do not desire to limit myself to the specific details of procedureherein set forth, as it is obvious that various modifications may bemade therein, without departing from the essential features of myinvention, as defined in the appended claims.

I claim:

1. A viscose (cellulose sulphocarbonate) complex including normalviscose in association with less than five per cent tri-sodiuinphosphate (Na PO in such proportion as to accelerate the progressiveincrement of maturity of the normal viscose.

2. A viscose (cellulose sulphocarbonate) complex including normalviscose in association with tri-sodium phosphate (Na POg in suchproportion as to accelerate the progressive increment of maturity of thenormal viscose, said proportion being from afraction of one per cent, tofour and one-half per cent, of the cellulose content of the viscose.

3. Viscose mixed with tri-sodium phosphate (Na PO in such proportion asto acc derate the progressive increment of matu 'y of the vi tie, said.proportion being from a fraction or one per cent, to four and onehalttper cent, oi the cellulose content of the viscose.

4. A liquid cellulose sulphocarbonate complex including tri-sodiumphosphate.

A liquid alkali cellulose complex includ ing tri-sodium phosphate insuch proportion as to accelerate the aging of such cellulose, saidproportion being from a fraction of one per cent, to four and onehalfper cent, of the cellulose content of the complex.

6. The method of accelerating the more ment of maturity of normalviscose, which consists in adding tri-sodiuin phosphate to such viscose.

In testimony whereof, I have hereunto signed my name at Burlington, NewJersey, this 20th day of May, 1925.

IVILLIAM MENDEL.

CERTIFICATE OF CORRECTION.

Patent No. 1,773,923. Granted August 26, 1930, to

WILLIAM MENDEL.

d specification of the Page 2, line 19, followinsert the words"Satisfactory results may he s than five per cen t of said phosphate";and that the said Let ters Patent should be read with this t the samemay conform the case in the Patent Office.

I M. J. Moore, (Seal) Acting Commissioner of Patents.

